Electrical coupling device and electrical connector

ABSTRACT

An electrical coupling device is provided for bringing various electrical members into electrical connection and also for disconnecting them, the device utilizing electrical connector components in which the manner of connection and disconnection is push-pull, good electrical contact being obtained in the connector components by means of an outward force exerted by a Belleville washer, manipulatable means being provided to bring electrical connector components into and out of engagement.

tates atent H 1 3,644,869

Newman Feb. 22, 1972 541 ELECTRICAL COUPLING DEVICE AND 2,697,21212/1954 Castelli ..339/111 ELECTRICAL CONNECTOR 2,851,670 9/1958 Senior..339/75 3,031,641 41 62 C [72] lnventor: Albert 1?. Newman, SpringfieldTownship, 3 083 781 4 3 2522 et 31 3 2 Hamilton County Ohio [73]Assignee: Empire Products, Inc., Cincinnati, Ohio Primary ExaminerMarvinA. Champion I Assistant Examiner-Robert A. Hafer [22] Flled' 1969Attorney-John W. Melville, Albert E, Strasser, John D. [21] Appl.No.:873,248 Hayes, Stanley H. Foster, Joseph V. Hoffman, Gibson R.

Yungbliet and Charles H. Melville [52] U.S.Cl ..339/19 339/111,?139/174,

339/252 P, 339/263 R, 24/214 [57] ABSTRACT [51] Int. Cl .1101! 31/08,H01! 1 1/22 An electrical coupling device is provided for bringingvarious Flew Search "339/19, 22 B, 258 R, 263, 1 electrical members intoelectrical connection and also for disconnecting them, the deviceutilizing electrical connector 180/95; 287/126 components in which themanner of connection and disconnection is push-pull, good electricalcontact being obtained in [56] References Cited the connector componentsby means of an outward force ex- UNITED STATES PATENTS erted by aBelleville washer, manipulatable means being provided to bringelectrical connector components into and out 1 Dodgson -.--.339/1 1 l Xofengagement 2,343,675 3/1944 Kenyon 2,502,634 4/1950 Smith ..339/2129Claims,7l)rawingFigures PATENTEU FEB 22 I972 SHEET 2 BF 3 INVENTORALBERT P. NEWMAN ATTORNEY PATENTEBFEB 22 I972 SHEET 3 OF 3 I INVENTORALBERT P. NEWMAN ATTORNEY ELECTRICAL COUPLING DEVICE AND ELECTRICALCONNECTOR This invention relates to electrical connectors and moreparticularly to such connectors for use in interconnecting electricalcable ends, or alternatively for interconnecting an electrical cable endwith a fixed mating connector.

In the creation of electrical connectors for the indicated use, certaincriteria must be met. It is important that following interconnection ofmating connectors the connection itself present resistance in theelectrical line which is as small as possible. Otherwise stated, themating connectors must be as efficient as possible in the transmissionof electrical power. Deleterious to this end are any gaps betweencontact surfaces in mating connectors because such gaps serve as causesof resistance and make for inefficiency in the interconnection ofconnectors. A second criterion is that mating connectors remaininterconnected so long as it is desired that power pass through theinterconnection, while yet being reasonably easily disconnected when sodesired.

In the prior art connectors are known which meet both of these criteriaby employing cam action which depends upon mutual rotation of matingconnectors, conductor surfaces being forced into close proximity onmutual rotation of the mating connector, while the active member causingthe movement into close proximity serves also as a means for inhibitingseparation of mating connectors until counter rotation takes place.While such connectors are satisfactory and meet both criteria heretoforestated, certain applications do not permit mutual rotation of matingconnectors. Among such applications is that where the material of theconnectors will seize or otherwise not tolerate rotation. Such a resultoccurs, for example, when the connector material is copper.

Accordingly, it is the primary objective of the present invention tomeet the criteria set out in mating connectors where mutual rotation isnot desirable or permissible, but instead mate upon a straight linepush-pull manner of engagement and disengagement. Where interengagementis straight line in manner, reflection will indicate to the thoughtfulperson that the two criteria set forth above are mutually inconsistent.Close contact between conductive walls bespeaks tight fit between matingmembers, while friction which will normally result from such tight fitwill create difficulty in separation of mating connectors when it isdesired to break contact. The present invention meets the challenge ofproviding mating connectors which mate upon a straight line movement,which upon interengagement give efficient transmission of electricalpower, and at the same time admit of reasonable ease in separation ofmating connectors when it is desired to separate them. This is achievedby dividing the male contact of mating connectors into a plurality ofsegments with the various segments normally being in effectspring-loaded outwardly. This scheme provides a male connector whichwhile being able to contract for engagement with a female connector,will yet following engagement be in intimate contact with the conductivesurfaces in the female. In order to achieve the spring load effect,Belleville washers are employed disposed between segments of the malecontact. A supplemental object of the present invention is to provideconnectors which may be fabricated without overly elaboratemanufacturing operations, so that economy in the production ofconnectors is possible.

How these and many other objects are to be implemented will become clearthrough a consideration of the accompanying drawings wherein:

FIG. 1 shows a side view of male and female connectors embodying thepresent invention in electrically engaged relationship,

FIG. 2 is a side view of a male connector constructed according to thepresent invention,

FIG. 3 is a section at 3-3 of FIG. 2,

FIG. 4 is a section at 4-4 of FIG. 3,

FIG. 5 is a front view of a structure embodying an application of thepresent invention,

FIG. 6 is a plan view, partly schematic, of the structure shown in FIG.5, and

FIG. 7 is a section at 7-7 of FIG. 6.

In the drawings, FIGS. 1-4 show for illustrative purposes an assembly ofmale and female connectors for releasably bringing into contact twoelectrical cable ends 10 and 11. A female connector 12 is shown having acrimp tube 13 as an integral part thereof, such crimp tube receivingtherein the conductive strands 14 of cable end 11. Crimp tube 13 is ofdeformable copper, and after such conductive strands are insertedtherein, a crimping device is applied to deform such crimp tube 13 intothe conductors and thereby retain them in place in contact with femaleconnector 12. An insulating sleeve 15 is shown in phantom disposed aboutfemale connector 12 to protect such connector as well as any bareportions of conductors 14 within cable and 11 from accidental contact byusers.

Disposed within recess 16 of female connector 12 is contact portion 20of male connector 21. Male connector 21 also has a crimp tube 22integral therewith within which conductive strands 23 of cable 10 arereceived, crimp tube 22 being deformed following insertion of conductivestrands therein to retain such strands in contact with male connector21. A protective insulating sleeve 24, shown in phantom, is disposedabout male connector 21 and any exposed portion of conductors 23 toprevent contact by operators therewith.

What is here contemplated is a push-pull male and female connectorarrangement whereby the male contact portion 20 is firmly held withinthe recess 16 of female connector 12 when it is desired that the maleand female connectors be in contact. When not so desired, suchconnectors may be separated simply by pulling them apart. Theirreengagement may be in like manner simply achieved by pushing thecontact portion of male connector 21 into recess 16 of female connector12.

Ready, releasable, manual interengagement is possible consistently withfirm electrical connection when engaged by reason of the now to bedescribed expedient. Male connector 21 is drilled through to providehole 25. Contact portion 20 is bifurcated into two segments by slit 26which opens into hole 25 as well as into the free end of contact portion20. A Belleville washer 30 is disposed within slit 26. Washer 30 is heldin place by means of a fixing stud 31 which is driven into passage 32formed in contact portion 20. Fixing stud 31 is retained within passage32 by friction, and such fixing stud 31 passes through aperture 33 inBelleville washer 30 whereby such washer is held in position within slit26. The Belleville washer is a well-known type of metal washer which maybe described as truncated conical in configuration. Such washers have anaperture therethrough such as 33 and are of resilient metal.

By means of disposition of such a washer within slit 26 in contactportion 20, the two halves of such contact portion are normally urgedoutwardly from each other and a normal diameter in said contact portionis provided.

The diameter of recess 16 is slightly smaller than such normal diameterof contact portion 20. When contact portion 20 is then presented atrecess 16, the rounded edges at the free end of contact portion 20 willengage walls of recess 16 and a force compressing the two halves ofcontact portion 20 against the outward force of Belleville washer 30will be exerted. The two halves will be forced together until thediameter of the combined halves of contact portion 20 is such thatcontact portion 20 mayslide into recess 16. While the contact portion isin place within recess 16 the compressed Belleville washer 30 willcontinue to exert an outward force, thereby assuring a firm contactbetween the external surface of contact portion 20 and the internalsurface of recess 16.

The connectors described herein are especially useful where it isdesired that the connectors be made out of unalloyed copper or othersoft material for purposes of minimizing connector size for a givenelectrical load. Such connectors will seize if a connector constructionrequiring rotation is employed, and a very short connector life willresult. The present connector construction, not requiring rotation, ismuch more suitable for such applications. I have also found that acoating of silver or other conductive soft metal if applied to theconnectors here provided, acts as a lubricant and serves to extend thelife of the connectors on repeated cycles of engagement anddisengagement.

Further illustrations FIGS. 5, 6 and 7 illustrate an application forreleasable electrical interconnection in the railroad engine field wherethe present invention has been found particularly useful. The usefulrailroad engine of our time utilizes a plurality of traction motors todrive the engine wheels, and a generator carried within the enginedrives the traction motors. Normal practice with railroads is from timeto time to disconnect the means for conveying electrical power from thegenerator to the motors, so that the generator may be tested as to theadequacy with which it is functioning. The flow of power between motorand generator is reestablished following the test.

Neither traction motors nor generator are shown in the drawings becausesuch showing is unnecessary for a description of the present invention.A mounting bar 34 of nonconductive material is affixed by bolts or otherknown means to a bulkhead 35 or like fixed surface in a railroad engine.Bus bar 36 is electrically tapped by a cable attached thereto (notshown) for power for such traction motors. Male connector 37 is securedto bus bar 36 by means of bolts 39. Bolt 40 having hexagonal head 400then holds the assembly consisting of bus bar 36 and male connector 37mounted upon mounting bar 34. A second bus bar 36a to service additionaltraction motors is also held in relation to mounting bar 34 by bolt 40.Additional conductive plate 41 is present in order to bear a portion ofthe electrical load from male connector 37, which eventually flows tobus bars 36 and 36a. It will be observed that plate 41 on one side has aprojection 42 extending beyond bus bar 34 at one side in FIG. 6 for apurpose hereafter to be described.

Bus bar 48 is associated with the positive side of a generator, and amale connector 49 is mounted upon such bus bar 48 by means of bolts 51.Bolt 52 having a hexagonal head 52a then secures bus bar 48 to whichmale connector 49 has been assembled to mounting bar 40. Bolt 52 alsoholds conductive taps 46 and 47 which lead to the generator, in contactwith bus bar 48.

In normal operation of the here posited railroad engine, electricalconnection between the positive side of the generator by means of maleconnector 49 which is in electrical contact with such positive side, andthe traction motor through its male connector 37, is necessary. It iscontemplated that this be accomplished by means of the presentinvention, by utilizing a shunt assembly, in the present embodimentconsisting of two female connectors 53 and 54 for respective engagementwith male connectors 49 and 37. Female connectors 53 and 54 are boltedto a shunt bar 55 by means of bolts 56 and 57 respectively.

In order that male connectors 49 and 37 receive female connectors 53 and54 in accordance with the present apparatus, it is desirable that suchmale connectors extend the same distance from mounting bar 34. This isaccomplished by utilizing the spacers 58 and 59 on the traction motorside, and 60 and 61 on the generator side. Spacers 59 and 61 are ofconductive material, while those at 58 and 60 need not be.

This assembly consisting of shunt bar 55 and the female connectors 53and 54 secured thereto is held in operative position by means of bolt orrod 62 which is threaded at one end 63, there passing through a hole 420in projection 42 of bus bar 41, bolt 62 clearing the walls of hole 42a.Threads 63 of rod 62 do not thread into the material of plate 41 becausethe material of such bolt, preferably steel, might bind upon rotationwithin the conductive material of plate 41 which may be of copper.Instead such threads 63 are threaded into internal threads tapped intosteel strip 64 which is secured to projection 4-2 by means of bolts 640.A thrust collar 65 is secured by means of setserew 65a to bolt 62 on oneside of shunt bar 55, while hexagonal head 66 is integral with bolt 62.Thus manipulation of head 66 (and hence bolt 62) in one direction willcause engagement of female connectors 53 and 54 with male connectors 49and 37 respectively, and this is the condition shown in solid lines inFIG. 6 of the drawings. When manipulation of head 66 for movement towardengagement as shown in solid lines is desired, head 66 will be rotatedby a wrench or other suitable tool applied thereto, and during rotationsuch head will bear against shunt bar 55.

When, on the other hand, it is desired to disengage such femaleconnectors from such male connectors head 66 (and hence bolt 62) isrotated in the opposite direction, following which the shunt bar 55 andfemale connector 53 and 54 assembly will assume the position out ofcontact with the male connectors, such alternative position being shownin broken lines in FIG. 6. When head 66 is rotated in such oppositedirection for the purpose of disengaging to the broken line positionshown, it is thrust collar 65 which bears against shunt bar 55.

FIG. 7 is a section taken at 77 in FIG. 6 and shows the employment of analternative male connector according to the present invention to thatseen in FIGS. 1-4. Two slits 70 and 71 divide male connector 37 intofour segments 72-75. Belleville washers 7679 are disposed within slits70 and 71 between each pair of segments in the group 72-75. Fixing studs84-87, each of which passes through the aperture in the Bellevillewasher, are driven into passages in the various segments within whichthe studs are then retained by friction. The studs and hence theBelleville washers are thus retained in place. It will be understoodthat male connector 49 is identical in construction to that justdescribed for male connector 37 and therefore further description is notnecessary.

In order to complete the description of the utility of the presentinvention as applied to railroad engine testing, following removal offemale connector 53 from male connector 49, whereby electricalinterconnection of generator and traction motor is broken, a separatetest conductor terminating in a female connector of the sameconstruction as described for female connector 53 is engaged with maleconnector 49. A generator may thereby be operated, its electrical outputbeing led to a test board where its ability to function to acceptablestandards is verified. Following the test procedure, such test lead isremoved and by means of the shunt bar and male connector assemblyheretofore described, the motive power of the railroad engine may veryquickly be returned to its normal running state.

It should be noted that the present invention is useful forinterengaging other electrical means than traction motors andgenerators. Therefore, it will be appreciated that while I havedescribed a specific application of this invention, other applicationsand embodiments entailing changes and modification in nonessentialaspects of the invention can be made, and such applications andmodifications can still fall within the ambit of my invention.

Iclaim:

1. An electrical coupling device comprising at least two firstelectrical connectors mounted in fixed position, each of said electricalconnectors being in electrical contact with an electrical means,

a shunt assembly comprising a conductive shunt bar,

a mating electrical connector for each of said first electricalconnectors, each said mating electrical connector being mounted upon andin electrical contact with said shunt bar and being capable ofinterengaging with one of said first electrical connectors, said firstelectrical connectors and said mating electrical connector for eachthereof comprising pairs of male and female connector means, and

control means for said shunt assembly capable of moving said shuntassembly in a first direction so that each of said first electricalconnectors is simultaneously engaged by a said mating electricalconnector, and also capable of moving said shunt assembly in a seconddirection so that disengagement of said first electrical connectors andsaid mating electrical connectors will occur.

2. An electrical coupling device as claimed in claim 1 wherein at leastone of said electrical connectors comprises a male connector having acontact portion and an external surface on said contact portion, andpressure means within said contact portion for exerting a force urgingsaid external surface on said contact portion outwardly.

3. An electrical coupling device as claimed in claim 2 wherein saidpressure means comprises a slit in said contact portion dividing saidcontact portion into a plurality of segments,

a Belleville washer within said slit,

and means for retaining said Belleville washer within said slit,

whereby said Belleville washer exerts said force urging said externalsurface on said control portion outwardly.

4. An electrical coupling device as claimed in claim 3 wherein saidcontrol means comprises fixed means disposed in fixed relationship tosaid first electrical connectors, and

manipulation means in engagement both with said fixed means and saidshunt assembly, operation of said manipulable means being capable ofmoving said shunt assembly in said first and second direction.

5. An electrical coupling device as claimed in claim 4 wherein saidfixed means comprises an internally threaded member and said manipulablemeans comprises bolt means in said shunt bar, freely rotatable therein,said bolt means having a threaded end in engagement with said internallythreaded member, and

head and thrust collar means fixedly mounted on said bolt means onopposite sides of said shunt bar, said head bearing on said shunt barwhen movement of said shunt assembly in said first direction is desired,and said thrust collar bearing on said shunt bar when movement of saidshunt assembly in said second direction is desired.

6. An electrical connector for use with a mating connector having aninternal recess, comprising a male connector having a contact portionand an external surface on said contact portion,

a slit in said contact portion dividing said contact portion into aplurality of segments,

a Belleville washer within said slit, and

retaining means for retaining said Belleville washer within said slit.

7. An electrical connector as claimed in claim 6 wherein said Bellevillewasher has an aperture therethrough and said retaining means comprises astud passing through said aperture, said stud being frictionally fixedwithin at least one of said segments.

8. An electrical connector as claimed in claim 6 wherein said maleconnector is normally oversize relative to said internal recess in saidmating connector, said contact portion being capable of contractingagainst the outward force of said Bel leville washer to a size whichwill fit into said internal recess, whereby said contact portion whiledisposed within said internal recess will have its external surfaceurged outwardly into intimate contact with said internal recess.

9. An electrical connector as claimed in claim 8 wherein a coating ofsilver is applied to said external surface of said contact portion..

1. An electrical coupling device comprising at least two firstelectrical connectors mounted in fixed position, each of said electricalconnectors being in electrical contact with an electrical means, a shuntassembly comprising a conductive shunt bar, a mating electricalconnector for each of said first electrical connectors, each said matingelectrical connector being mounted upon and in electrical contact withsaid shunt bar and being capable of interengaging with one of said firstelectrical connectors, said first electrical connectors and said matingelectrical connector for each thereof comprising pairs of male andfemale connector means, and control means for said shunt assemblycapable of moving said shunt assembly in a first direction so that eachof said first electrical connectors is simultaneously engaged by a saidmating electrical connector, and also capable of moving said shuntassembly in a second direction so that disengagement of said firstelectrical connectors and said mating electrical connectors will occur.2. An electrical coupling device as claimed in claim 1 wherein at leastone of said electrical connectors comprises a male connector having acontact portion and an external surface on said contact portion, andpressure means within said contact portion for exerting a force urgingsaid external surface on said contact portion outwardly.
 3. Anelectrical coupling device as claimed in claim 2 wherein said pressuremeans comprises a slit in said contact portion dividing said contactportion into a plurality of segments, a Belleville washer within saidslit, and means for retaining said Belleville washer within said slit,whereby said Belleville washer exerts said force urging said externalsurface on said control portion outwardly.
 4. An electrical couplingdevice as claimed in claim 3 wherein said control means comprises fixedmeans disposed in fixed relationship to said first electricalconnectors, and manipulation means in engagement both with said fixedmeans and said shunt assembly, operation of said manipulable means beingcapable of moving said shunt assembly in said first and seconddirection.
 5. An electrical coupling device as claimed in claim 4wherein said fixed means comprises an internally threaded member andsaid manipulable means comprises bolt means in said shunt bar, freelyrotatable therein, said bolt means having a threaded end in engagementwith said internally threaded member, and head and thrust collar meansfixedly mounted on said bolt means on opposite sides of said shunt bar,said head bearing on said shunt bar when movement of said shunt assemblyin said first direction is desired, and said thrust collar bearing onsaid shunt bar when movement of said shunt assembly in said seconddirection is desired.
 6. An electrical connector for use with a matingconnector having an internal recess, comprising a male connector havinga contact portion and an external surface on said contact portion, aslit in said contact portion dividing said contact portion into aplurality of segments, a Belleville washer within said slit, andretaining means for retaining said Belleville washer within said slit.7. An electrical connector as claimed in claim 6 wherein said Bellevillewasher has an aperture therethrough and said retaining means comprises astud passing through said aperture, said stud being frictionally fixedwithin at least one of said segments.
 8. An electrical connector asclaimed in claim 6 wherein said male connector is normally oversizerelative to said internal recess in said mating connector, said contactportion being capable of contracting against the outward force of saidBelleville washer to a size which will fit into said internal recess,whereby said contact portion while disposed within said internal recesswill have its external surface urged outwardly into intimate contactwith said internal recess.
 9. An electrical connector as claimed inclaim 8 wherein a coating of silver is applied to said external surfaceof said contact portion.